In trains in service in recent years, for the purpose of a more comfortable service and a more efficient and safe service, a digital transmission line is used for communication between car-mounted apparatuses of cars such as doors, air conditioners, brakes, motors, ATOs, SIVs, and automatic broadcast apparatuses and a train control apparatus for collecting, monitoring, and controlling train information. However, because a larger-capacity digital transmission line can be applied according to the network technology in recent years, delivery of video information and the like is also possible.
For the delivery of the video information and the like, there are an application in which a driver and a crew member collect and monitor video information from a fixed camera provided in a station platform and an application of passenger service such as delivery of information beneficial to passengers, for example, information concerning a train service such as destination guidance, next station guidance, stop guidance, and service information (arrival time change guidance), news, weather forecast, advertisements, and regional information (peculiar information around a stop).
In the system in the past of this type, when service image content is displayed, several seconds are necessary to read compressed content data and, at the same time, decompress the read data and expand the data in a memory, and display the data. Therefore, there is a problem in that there is a no-display period (hereinafter referred to as “blank”) clearly noticed by human eyes at display switching time from a service image to a service image.
On the other hand, in a system disclosed in Patent Literature 1, a service image is expanded and prepared in advance before display and content switching of a display command is timed, whereby switching from a currently-displayed service image to the prepared service image is seamlessly performed.